[enh] settings.yml: add use_default_settings option (2nd version)

14 files changed, 437 insertions, 249 deletions

diff --git a/Makefile b/Makefile
index 94309cefe..29faaeefa 100644
--- a/Makefile
+++ b/Makefile
@@ -266,19 +266,4 @@ test.clean:
 travis.codecov:
 	$(Q)$(PY_ENV_BIN)/python -m pip install codecov
 
-
-# user-settings
-# -------------
-
-PHONY += user-settings.create user-settings.update
-
-user-settings.update:  pyenvinstall
-	$(Q)$(PY_ENV_ACT); pip install ruamel.yaml
-	$(Q)$(PY_ENV_ACT); python utils/update_user_settings.py ${SEARX_SETTINGS_PATH}
-
-user-settings.update.engines:  pyenvinstall
-	$(Q)$(PY_ENV_ACT); pip install ruamel.yaml
-	$(Q)$(PY_ENV_ACT); python utils/update_user_settings.py --add-engines ${SEARX_SETTINGS_PATH}
-
-
-.PHONY: $(PHONY)
\ No newline at end of file
+.PHONY: $(PHONY)
diff --git a/docs/admin/settings.rst b/docs/admin/settings.rst
index cd944cc4c..532b99752 100644
--- a/docs/admin/settings.rst
+++ b/docs/admin/settings.rst
@@ -235,68 +235,51 @@ In the following example, the actual settings are the default settings defined i
 
 .. code-block:: yaml
 
-  use_default_settings: true
+  use_default_settings: True
   server:
       secret_key: "uvys6bRhKHUdFF5CqbJonSDSRN8H0sCBziNSrDGNVdpz7IeZhveVart3yvghoKHA"
-  server:
       bind_address: "0.0.0.0"
 
-With ``use_default_settings: True``, each settings can be override in a similar way with one exception, the ``engines`` section:
-
-* If the ``engines`` section is not defined in the user settings, searx uses the engines from the default setttings (the above example).
-* If the ``engines`` section is defined then:
-
-   * searx loads only the engines declare in the user setttings.
-   * searx merges the configuration according to the engine name.
+With ``use_default_settings: True``, each settings can be override in a similar way, the ``engines`` section is merged according to the engine ``name``.
 
-In the following example, only three engines are available. Each engine configuration is merged with the default configuration.
+In this example, searx will load all the engine and the arch linux wiki engine has a :ref:`token<private engines>`:
 
 .. code-block:: yaml
 
-  use_default_settings: true
+  use_default_settings: True
   server:
       secret_key: "uvys6bRhKHUdFF5CqbJonSDSRN8H0sCBziNSrDGNVdpz7IeZhveVart3yvghoKHA"
   engines:
-    - name: wikipedia
-    - name: wikidata
-    - name: ddg definitions
+    - name: arch linux wiki
+      tokens: ['$ecretValue']
 
-Another example where four engines are available. The arch linux wiki engine has a :ref:`token<private engines>`.
+It is possible to remove some engines from the default settings. The following example is similar to the above one, but searx doesn't load the the google engine:
 
 .. code-block:: yaml
 
-  use_default_settings: true
+  use_default_settings:
+      engines:
+         remove:
+           - google
   server:
       secret_key: "uvys6bRhKHUdFF5CqbJonSDSRN8H0sCBziNSrDGNVdpz7IeZhveVart3yvghoKHA"
   engines:
     - name: arch linux wiki
       tokens: ['$ecretValue']
-    - name: wikipedia
-    - name: wikidata
-    - name: ddg definitions
-
-automatic update
-----------------
-
-The following comand creates or updates a minimal user settings (a secret key is defined if it is not already the case):
-
-.. code-block:: sh
-
-  make SEARX_SETTINGS_PATH=/etc/searx/settings.yml user-settings.update
-
-Set ``SEARX_SETTINGS_PATH`` to your user settings path.
 
-As soon the user settings contains an ``engines`` section, it becomes difficult to keep the engine list updated.
-The following command creates or updates the user settings including the ``engines`` section:
+As an alternative, it is possible to specify the engines to keep. In the following example, searx has only two engines:
 
-.. code-block:: sh
-
-  make SEARX_SETTINGS_PATH=/etc/searx/settings.yml user-settings.update.engines
-
-After that ``/etc/searx/settings.yml``
-
-* has a ``secret key``
-* has a ``engine`` section if it is not already the case, moreover the command:
+.. code-block:: yaml
 
-  * has deleted engines that do not exist in the default settings.
-  * has added engines that exist in the default settings but are not declare in the user settings.
+  use_default_settings:
+      engines:
+         keep_only:
+           - google
+           - duckduckgo
+  server:
+      secret_key: "uvys6bRhKHUdFF5CqbJonSDSRN8H0sCBziNSrDGNVdpz7IeZhveVart3yvghoKHA"
+  engines:
+    - name: google
+      tokens: ['$ecretValue']
+    - name: duckduckgo
+      tokens: ['$ecretValue']
diff --git a/searx/__init__.py b/searx/__init__.py
index 214e554d4..9bbc7c8c3 100644
--- a/searx/__init__.py
+++ b/searx/__init__.py
@@ -16,7 +16,7 @@ along with searx. If not, see < http://www.gnu.org/licenses/ >.
 '''
 
 import logging
-import searx.settings
+import searx.settings_loader
 from os import environ
 from os.path import realpath, dirname, join, abspath, isfile
 
@@ -24,7 +24,7 @@ from os.path import realpath, dirname, join, abspath, isfile
 searx_dir = abspath(dirname(__file__))
 engine_dir = dirname(realpath(__file__))
 static_path = abspath(join(dirname(__file__), 'static'))
-settings, settings_load_message = searx.settings.load_settings()
+settings, settings_load_message = searx.settings_loader.load_settings()
 
 if settings['ui']['static_path']:
     static_path = settings['ui']['static_path']
diff --git a/searx/settings.py b/searx/settings.py
deleted file mode 100644
index cdddff589..000000000
--- a/searx/settings.py
+++ /dev/null
@@ -1,91 +0,0 @@
-import collections.abc
-
-import yaml
-from searx.exceptions import SearxSettingsException
-from os import environ
-from os.path import dirname, join, abspath, isfile
-
-
-searx_dir = abspath(dirname(__file__))
-
-
-def check_settings_yml(file_name):
-    if isfile(file_name):
-        return file_name
-    else:
-        return None
-
-
-def load_yaml(file_name):
-    try:
-        with open(file_name, 'r', encoding='utf-8') as settings_yaml:
-            settings = yaml.safe_load(settings_yaml)
-            if not isinstance(settings, dict) or len(settings) == 0:
-                raise SearxSettingsException('Empty file', file_name)
-            return settings
-    except IOError as e:
-        raise SearxSettingsException(e, file_name)
-    except yaml.YAMLError as e:
-        raise SearxSettingsException(e, file_name)
-
-
-def get_default_settings_path():
-    return check_settings_yml(join(searx_dir, 'settings.yml'))
-
-
-def get_user_settings_path():
-    # find location of settings.yml
-    if 'SEARX_SETTINGS_PATH' in environ:
-        # if possible set path to settings using the
-        # enviroment variable SEARX_SETTINGS_PATH
-        return check_settings_yml(environ['SEARX_SETTINGS_PATH'])
-    else:
-        # if not, get it from searx code base or last solution from /etc/searx
-        return check_settings_yml('/etc/searx/settings.yml')
-
-
-def update_dict(d, u):
-    for k, v in u.items():
-        if isinstance(v, collections.abc.Mapping):
-            d[k] = update_dict(d.get(k, {}), v)
-        else:
-            d[k] = v
-    return d
-
-
-def update_settings(default_settings, user_settings):
-    for k, v in user_settings.items():
-        if k == 'use_default_settings':
-            continue
-        elif k == 'engines':
-            default_engines = default_settings[k]
-            default_engines_dict = dict((definition['name'], definition) for definition in default_engines)
-            default_settings[k] = [update_dict(default_engines_dict[definition['name']], definition)
-                                   for definition in v]
-        else:
-            update_dict(default_settings[k], v)
-
-    return default_settings
-
-
-def load_settings(load_user_setttings=True):
-    default_settings_path = get_default_settings_path()
-    user_settings_path = get_user_settings_path()
-    if user_settings_path is None or not load_user_setttings:
-        # no user settings
-        return (load_yaml(default_settings_path),
-                'load the default settings from {}'.format(default_settings_path))
-
-    # user settings
-    user_settings = load_yaml(user_settings_path)
-    if user_settings.get('use_default_settings'):
-        # the user settings are merged with the default configuration
-        default_settings = load_yaml(default_settings_path)
-        update_settings(default_settings, user_settings)
-        return (default_settings,
-                'merge the default settings ( {} ) and the user setttings ( {} )'
-                .format(default_settings_path, user_settings_path))
-
-    # the user settings, fully replace the default configuration
-    return (user_settings,
-            'load the user settings from {}'.format(user_settings_path))
diff --git a/searx/settings_loader.py b/searx/settings_loader.py
new file mode 100644
index 000000000..172069bd5
--- /dev/null
+++ b/searx/settings_loader.py
@@ -0,0 +1,129 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+from os import environ
+from os.path import dirname, join, abspath, isfile
+from collections.abc import Mapping
+from itertools import filterfalse
+
+import yaml
+
+from searx.exceptions import SearxSettingsException
+
+
+searx_dir = abspath(dirname(__file__))
+
+
+def check_settings_yml(file_name):
+    if isfile(file_name):
+        return file_name
+    return None
+
+
+def load_yaml(file_name):
+    try:
+        with open(file_name, 'r', encoding='utf-8') as settings_yaml:
+            return yaml.safe_load(settings_yaml)
+    except IOError as e:
+        raise SearxSettingsException(e, file_name)
+    except yaml.YAMLError as e:
+        raise SearxSettingsException(e, file_name)
+
+
+def get_default_settings_path():
+    return check_settings_yml(join(searx_dir, 'settings.yml'))
+
+
+def get_user_settings_path():
+    # find location of settings.yml
+    if 'SEARX_SETTINGS_PATH' in environ:
+        # if possible set path to settings using the
+        # enviroment variable SEARX_SETTINGS_PATH
+        return check_settings_yml(environ['SEARX_SETTINGS_PATH'])
+
+    # if not, get it from searx code base or last solution from /etc/searx
+    return check_settings_yml('/etc/searx/settings.yml')
+
+
+def update_dict(default_dict, user_dict):
+    for k, v in user_dict.items():
+        if isinstance(v, Mapping):
+            default_dict[k] = update_dict(default_dict.get(k, {}), v)
+        else:
+            default_dict[k] = v
+    return default_dict
+
+
+def update_settings(default_settings, user_settings):
+    # merge everything except the engines
+    for k, v in user_settings.items():
+        if k not in ('use_default_settings', 'engines'):
+            update_dict(default_settings[k], v)
+
+    # parse the engines
+    remove_engines = None
+    keep_only_engines = None
+    use_default_settings = user_settings.get('use_default_settings')
+    if isinstance(use_default_settings, dict):
+        remove_engines = use_default_settings.get('engines', {}).get('remove')
+        keep_only_engines = use_default_settings.get('engines', {}).get('keep_only')
+
+    if 'engines' in user_settings or remove_engines is not None or keep_only_engines is not None:
+        engines = default_settings['engines']
+
+        # parse "use_default_settings.engines.remove"
+        if remove_engines is not None:
+            engines = list(filterfalse(lambda engine: (engine.get('name')) in remove_engines, engines))
+
+        # parse "use_default_settings.engines.keep_only"
+        if keep_only_engines is not None:
+            engines = list(filter(lambda engine: (engine.get('name')) in keep_only_engines, engines))
+
+        # parse "engines"
+        user_engines = user_settings.get('engines')
+        if user_engines:
+            engines_dict = dict((definition['name'], definition) for definition in engines)
+            for user_engine in user_engines:
+                default_engine = engines_dict.get(user_engine['name'])
+                if default_engine:
+                    update_dict(default_engine, user_engine)
+                else:
+                    engines.append(user_engine)
+
+        # store the result
+        default_settings['engines'] = engines
+
+    return default_settings
+
+
+def is_use_default_settings(user_settings):
+    use_default_settings = user_settings.get('use_default_settings')
+    if use_default_settings is True:
+        return True
+    if isinstance(use_default_settings, dict):
+        return True
+    if use_default_settings is False or use_default_settings is None:
+        return False
+    raise ValueError('Invalid value for use_default_settings')
+
+
+def load_settings(load_user_setttings=True):
+    default_settings_path = get_default_settings_path()
+    user_settings_path = get_user_settings_path()
+    if user_settings_path is None or not load_user_setttings:
+        # no user settings
+        return (load_yaml(default_settings_path),
+                'load the default settings from {}'.format(default_settings_path))
+
+    # user settings
+    user_settings = load_yaml(user_settings_path)
+    if is_use_default_settings(user_settings):
+        # the user settings are merged with the default configuration
+        default_settings = load_yaml(default_settings_path)
+        update_settings(default_settings, user_settings)
+        return (default_settings,
+                'merge the default settings ( {} ) and the user setttings ( {} )'
+                .format(default_settings_path, user_settings_path))
+
+    # the user settings, fully replace the default configuration
+    return (user_settings,
+            'load the user settings from {}'.format(user_settings_path))
diff --git a/tests/unit/settings/empty_settings.yml b/tests/unit/settings/empty_settings.yml
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/unit/settings/empty_settings.yml
diff --git a/tests/unit/settings/syntaxerror_settings.yml b/tests/unit/settings/syntaxerror_settings.yml
new file mode 100644
index 000000000..6d3b0f9a0
--- /dev/null
+++ b/tests/unit/settings/syntaxerror_settings.yml
@@ -0,0 +1,2 @@
+Test:
+  **********
diff --git a/tests/unit/settings/user_settings.yml b/tests/unit/settings/user_settings.yml
new file mode 100644
index 000000000..f5b6c7173
--- /dev/null
+++ b/tests/unit/settings/user_settings.yml
@@ -0,0 +1,111 @@
+general:
+    debug : False
+    instance_name : "searx"
+
+search:
+    safe_search : 0
+    autocomplete : ""
+    default_lang : ""
+    ban_time_on_fail : 5
+    max_ban_time_on_fail : 120
+
+server:
+    port : 9000
+    bind_address : "0.0.0.0"
+    secret_key : "user_settings_secret"
+    base_url : False
+    image_proxy : False
+    http_protocol_version : "1.0"
+    method: "POST"
+    default_http_headers:
+        X-Content-Type-Options : nosniff
+        X-XSS-Protection : 1; mode=block
+        X-Download-Options : noopen
+        X-Robots-Tag : noindex, nofollow
+        Referrer-Policy : no-referrer
+
+ui:
+    static_path : ""
+    templates_path : ""
+    default_theme : oscar
+    default_locale : ""
+    theme_args :
+        oscar_style : logicodev
+
+engines:
+  - name : wikidata
+    engine : wikidata
+    shortcut : wd
+    timeout : 3.0
+    weight : 2
+
+  - name : wikibooks
+    engine : mediawiki
+    shortcut : wb
+    categories : general
+    base_url : "https://{language}.wikibooks.org/"
+    number_of_results : 5
+    search_type : text
+
+  - name : wikinews
+    engine : mediawiki
+    shortcut : wn
+    categories : news
+    base_url : "https://{language}.wikinews.org/"
+    number_of_results : 5
+    search_type : text
+
+  - name : wikiquote
+    engine : mediawiki
+    shortcut : wq
+    categories : general
+    base_url : "https://{language}.wikiquote.org/"
+    number_of_results : 5
+    search_type : text
+
+locales:
+    en : English
+    ar : العَرَبِيَّة (Arabic)
+    bg : Български (Bulgarian)
+    bo : བོད་སྐད་ (Tibetian)
+    ca : Català (Catalan)
+    cs : Čeština (Czech)
+    cy : Cymraeg (Welsh)
+    da : Dansk (Danish)
+    de : Deutsch (German)
+    el_GR : Ελληνικά (Greek_Greece)
+    eo : Esperanto (Esperanto)
+    es : Español (Spanish)
+    et : Eesti (Estonian)
+    eu : Euskara (Basque)
+    fa_IR : (fārsī) فارسى (Persian)
+    fi : Suomi (Finnish)
+    fil : Wikang Filipino (Filipino)
+    fr : Français (French)
+    gl : Galego (Galician)
+    he : עברית (Hebrew)
+    hr : Hrvatski (Croatian)
+    hu : Magyar (Hungarian)
+    ia : Interlingua (Interlingua)
+    it : Italiano (Italian)
+    ja : 日本語 (Japanese)
+    lt : Lietuvių (Lithuanian)
+    nl : Nederlands (Dutch)
+    nl_BE : Vlaams (Dutch_Belgium)
+    oc : Lenga D'òc (Occitan)
+    pl : Polski (Polish)
+    pt : Português (Portuguese)
+    pt_BR : Português (Portuguese_Brazil)
+    ro : Română (Romanian)
+    ru : Русский (Russian)
+    sk : Slovenčina (Slovak)
+    sl : Slovenski (Slovene)
+    sr : српски (Serbian)
+    sv : Svenska (Swedish)
+    te : తెలుగు (telugu)
+    ta : தமிழ் (Tamil)
+    tr : Türkçe (Turkish)
+    uk : українська мова (Ukrainian)
+    vi : tiếng việt (Vietnamese)
+    zh : 中文 (Chinese)
+    zh_TW : 國語 (Taiwanese Mandarin)
diff --git a/tests/unit/settings/user_settings_keep_only.yml b/tests/unit/settings/user_settings_keep_only.yml
new file mode 100644
index 000000000..518f18bde
--- /dev/null
+++ b/tests/unit/settings/user_settings_keep_only.yml
@@ -0,0 +1,14 @@
+use_default_settings:
+    engines:
+        keep_only:
+            - wikibooks
+            - wikinews
+server:
+    secret_key: "user_secret_key"
+    bind_address: "0.0.0.0"
+    default_http_headers:
+        Custom-Header: Custom-Value
+engines:
+    - name: wikipedia
+    - name: newengine
+      engine: dummy
diff --git a/tests/unit/settings/user_settings_remove.yml b/tests/unit/settings/user_settings_remove.yml
new file mode 100644
index 000000000..c4fd85df7
--- /dev/null
+++ b/tests/unit/settings/user_settings_remove.yml
@@ -0,0 +1,10 @@
+use_default_settings:
+    engines:
+        remove:
+            - wikibooks
+            - wikinews
+server:
+    secret_key: "user_secret_key"
+    bind_address: "0.0.0.0"
+    default_http_headers:
+        Custom-Header: Custom-Value
diff --git a/tests/unit/settings/user_settings_remove2.yml b/tests/unit/settings/user_settings_remove2.yml
new file mode 100644
index 000000000..e9be325dc
--- /dev/null
+++ b/tests/unit/settings/user_settings_remove2.yml
@@ -0,0 +1,15 @@
+use_default_settings:
+    engines:
+        remove:
+            - wikibooks
+            - wikinews
+server:
+    secret_key: "user_secret_key"
+    bind_address: "0.0.0.0"
+    default_http_headers:
+        Custom-Header: Custom-Value
+engines:
+    - name: wikipedia
+      tokens: ['secret_token']
+    - name: newengine
+      engine: dummy
diff --git a/tests/unit/settings/user_settings_simple.yml b/tests/unit/settings/user_settings_simple.yml
new file mode 100644
index 000000000..36e5f1647
--- /dev/null
+++ b/tests/unit/settings/user_settings_simple.yml
@@ -0,0 +1,6 @@
+use_default_settings: True
+server:
+    secret_key: "user_secret_key"
+    bind_address: "0.0.0.0"
+    default_http_headers:
+        Custom-Header: Custom-Value
diff --git a/tests/unit/test_settings_loader.py b/tests/unit/test_settings_loader.py
new file mode 100644
index 000000000..7df64e524
--- /dev/null
+++ b/tests/unit/test_settings_loader.py
@@ -0,0 +1,122 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+from os.path import dirname, join, abspath
+from unittest.mock import patch
+
+from searx.testing import SearxTestCase
+from searx.exceptions import SearxSettingsException
+from searx import settings_loader
+
+
+test_dir = abspath(dirname(__file__))
+
+
+class TestLoad(SearxTestCase):
+
+    def test_load_zero(self):
+        with self.assertRaises(SearxSettingsException):
+            settings_loader.load_yaml('/dev/zero')
+
+        with self.assertRaises(SearxSettingsException):
+            settings_loader.load_yaml(join(test_dir, '/settings/syntaxerror_settings.yml'))
+
+        with self.assertRaises(SearxSettingsException):
+            settings_loader.load_yaml(join(test_dir, '/settings/empty_settings.yml'))
+
+    def test_check_settings_yml(self):
+        self.assertIsNone(settings_loader.check_settings_yml('/dev/zero'))
+
+        bad_settings_path = join(test_dir, 'settings/syntaxerror_settings.yml')
+        self.assertEqual(settings_loader.check_settings_yml(bad_settings_path), bad_settings_path)
+
+
+class TestDefaultSettings(SearxTestCase):
+
+    def test_load(self):
+        settings, msg = settings_loader.load_settings(load_user_setttings=False)
+        self.assertTrue(msg.startswith('load the default settings from'))
+        self.assertFalse(settings['general']['debug'])
+        self.assertTrue(isinstance(settings['general']['instance_name'], str))
+        self.assertEqual(settings['server']['secret_key'], "ultrasecretkey")
+        self.assertTrue(isinstance(settings['server']['port'], int))
+        self.assertTrue(isinstance(settings['server']['bind_address'], str))
+        self.assertTrue(isinstance(settings['engines'], list))
+        self.assertTrue(isinstance(settings['locales'], dict))
+        self.assertTrue(isinstance(settings['doi_resolvers'], dict))
+        self.assertTrue(isinstance(settings['default_doi_resolver'], str))
+
+
+class TestUserSettings(SearxTestCase):
+
+    def test_is_use_default_settings(self):
+        self.assertFalse(settings_loader.is_use_default_settings({}))
+        self.assertTrue(settings_loader.is_use_default_settings({'use_default_settings': True}))
+        self.assertTrue(settings_loader.is_use_default_settings({'use_default_settings': {}}))
+        with self.assertRaises(ValueError):
+            self.assertFalse(settings_loader.is_use_default_settings({'use_default_settings': 1}))
+        with self.assertRaises(ValueError):
+            self.assertFalse(settings_loader.is_use_default_settings({'use_default_settings': 0}))
+
+    def test_user_settings_not_found(self):
+        with patch.dict(settings_loader.environ,
+                        {'SEARX_SETTINGS_PATH': '/dev/null'}):
+            settings, msg = settings_loader.load_settings()
+            self.assertTrue(msg.startswith('load the default settings from'))
+            self.assertEqual(settings['server']['secret_key'], "ultrasecretkey")
+
+    def test_user_settings(self):
+        with patch.dict(settings_loader.environ,
+                        {'SEARX_SETTINGS_PATH': join(test_dir, 'settings/user_settings_simple.yml')}):
+            settings, msg = settings_loader.load_settings()
+            self.assertTrue(msg.startswith('merge the default settings'))
+            self.assertEqual(settings['server']['secret_key'], "user_secret_key")
+            self.assertEqual(settings['server']['default_http_headers']['Custom-Header'], "Custom-Value")
+
+    def test_user_settings_remove(self):
+        with patch.dict(settings_loader.environ,
+                        {'SEARX_SETTINGS_PATH': join(test_dir, 'settings/user_settings_remove.yml')}):
+            settings, msg = settings_loader.load_settings()
+            self.assertTrue(msg.startswith('merge the default settings'))
+            self.assertEqual(settings['server']['secret_key'], "user_secret_key")
+            self.assertEqual(settings['server']['default_http_headers']['Custom-Header'], "Custom-Value")
+            engine_names = [engine['name'] for engine in settings['engines']]
+            self.assertNotIn('wikinews', engine_names)
+            self.assertNotIn('wikibooks', engine_names)
+            self.assertIn('wikipedia', engine_names)
+
+    def test_user_settings_remove2(self):
+        with patch.dict(settings_loader.environ,
+                        {'SEARX_SETTINGS_PATH': join(test_dir, 'settings/user_settings_remove2.yml')}):
+            settings, msg = settings_loader.load_settings()
+            self.assertTrue(msg.startswith('merge the default settings'))
+            self.assertEqual(settings['server']['secret_key'], "user_secret_key")
+            self.assertEqual(settings['server']['default_http_headers']['Custom-Header'], "Custom-Value")
+            engine_names = [engine['name'] for engine in settings['engines']]
+            self.assertNotIn('wikinews', engine_names)
+            self.assertNotIn('wikibooks', engine_names)
+            self.assertIn('wikipedia', engine_names)
+            wikipedia = list(filter(lambda engine: (engine.get('name')) == 'wikipedia', settings['engines']))
+            self.assertEqual(wikipedia[0]['engine'], 'wikipedia')
+            self.assertEqual(wikipedia[0]['tokens'], ['secret_token'])
+            newengine = list(filter(lambda engine: (engine.get('name')) == 'newengine', settings['engines']))
+            self.assertEqual(newengine[0]['engine'], 'dummy')
+
+    def test_user_settings_keep_only(self):
+        with patch.dict(settings_loader.environ,
+                        {'SEARX_SETTINGS_PATH': join(test_dir, 'settings/user_settings_keep_only.yml')}):
+            settings, msg = settings_loader.load_settings()
+            self.assertTrue(msg.startswith('merge the default settings'))
+            engine_names = [engine['name'] for engine in settings['engines']]
+            self.assertEqual(engine_names, ['wikibooks', 'wikinews', 'wikipedia', 'newengine'])
+            # wikipedia has been removed, then added again with the "engine" section of user_settings_keep_only.yml
+            self.assertEqual(len(settings['engines'][2]), 1)
+
+    def test_custom_settings(self):
+        with patch.dict(settings_loader.environ,
+                        {'SEARX_SETTINGS_PATH': join(test_dir, 'settings/user_settings.yml')}):
+            settings, msg = settings_loader.load_settings()
+            self.assertTrue(msg.startswith('load the user settings from'))
+            self.assertEqual(settings['server']['port'], 9000)
+            self.assertEqual(settings['server']['secret_key'], "user_settings_secret")
+            engine_names = [engine['name'] for engine in settings['engines']]
+            self.assertEqual(engine_names, ['wikidata', 'wikibooks', 'wikinews', 'wikiquote'])
diff --git a/utils/update_user_settings.py b/utils/update_user_settings.py
deleted file mode 100644
index fb6fd0b3f..000000000
--- a/utils/update_user_settings.py
+++ /dev/null
@@ -1,98 +0,0 @@
-#!/usr/bin/env python
-
-# set path
-from sys import path
-from os.path import realpath, dirname, join
-path.append(realpath(dirname(realpath(__file__)) + '/../'))
-
-import argparse
-import sys
-import string
-import ruamel.yaml
-import secrets
-import collections
-from ruamel.yaml.scalarstring import SingleQuotedScalarString, DoubleQuotedScalarString
-from searx.settings import load_settings, check_settings_yml, get_default_settings_path
-from searx.exceptions import SearxSettingsException
-
-
-RANDOM_STRING_LETTERS = string.ascii_lowercase + string.digits + string.ascii_uppercase
-
-
-def get_random_string():
-    r = [secrets.choice(RANDOM_STRING_LETTERS) for _ in range(64)]
-    return ''.join(r)
-
-
-def main(prog_arg):
-    yaml = ruamel.yaml.YAML()
-    yaml.preserve_quotes = True
-    yaml.indent(mapping=4, sequence=1, offset=2)
-    user_settings_path = prog_args.get('user-settings-yaml')
-
-    try:
-        default_settings, _ = load_settings(False)
-        if check_settings_yml(user_settings_path):
-            with open(user_settings_path, 'r', encoding='utf-8') as f:
-                user_settings = yaml.load(f.read())
-            new_user_settings = False
-        else:
-            user_settings = yaml.load('use_default_settings: True')
-            new_user_settings = True
-    except SearxSettingsException as e:
-        sys.stderr.write(str(e))
-        return
-
-    if not new_user_settings and not user_settings.get('use_default_settings'):
-        sys.stderr.write('settings.yml already exists and use_default_settings is not True')
-        return
-
-    user_settings['use_default_settings'] = True
-    use_default_settings_comment = "settings based on " + get_default_settings_path()
-    user_settings.yaml_add_eol_comment(use_default_settings_comment, 'use_default_settings')
-
-    if user_settings.get('server', {}).get('secret_key') in [None, 'ultrasecretkey']:
-        user_settings.setdefault('server', {})['secret_key'] = DoubleQuotedScalarString(get_random_string())
-
-    user_engines = user_settings.get('engines')
-    if user_engines:
-        has_user_engines = True
-        user_engines_dict = dict((definition['name'], definition) for definition in user_engines)
-    else:
-        has_user_engines = False
-        user_engines_dict = {}
-        user_engines = []
-
-    # remove old engines
-    if prog_arg.get('add-engines') or has_user_engines:
-        default_engines_dict = dict((definition['name'], definition) for definition in default_settings['engines'])
-        for i, engine in enumerate(user_engines):
-            if engine['name'] not in default_engines_dict:
-                del user_engines[i]
-
-    # add new engines
-    if prog_arg.get('add-engines'):
-        for engine in default_settings.get('engines', {}):
-            if engine['name'] not in user_engines_dict:
-                user_engines.append({'name': engine['name']})
-        user_settings['engines'] = user_engines
-
-    # output
-    if prog_arg.get('dry-run'):
-        yaml.dump(user_settings, sys.stdout)
-    else:
-        with open(user_settings_path, 'w', encoding='utf-8') as f:
-            yaml.dump(user_settings, f)
-
-
-def parse_args():
-    parser = argparse.ArgumentParser(description='Update user settings.yml')
-    parser.add_argument('--add-engines', dest='add-engines', default=False, action='store_true', help='Add new engines')
-    parser.add_argument('--dry-run', dest='dry-run', default=False, action='store_true', help='Dry run')
-    parser.add_argument('user-settings-yaml', type=str)
-    return vars(parser.parse_args())
-
-
-if __name__ == '__main__':
-    prog_args = parse_args()
-    main(prog_args)